Portions of the present application have been partially disclosed in the following Disclosure Document which is incorporated herein by reference:
Advanced Slow-Curing Fire Protection Materials Disclosure Document No. 462049, dated Sep. 13, 1999.
1. Field of Invention
The present invention relates to fire protection containers such as safes, storage boxes, filing cabinets, and other related applications, and to improved insulation materials incorporated therein.
2. Background of Art
Co-pending applications by Applicant describe a novel water-based silicate insulation material which has been used by Thermal Sciences, Inc. for production of fire protection containers under the FireCooler trademark. The material is essentially produced from a combination of sodium silicate solution with a high silica to soda ratio (about 3 to 4, i.e., commercial water glass) and a polyvalent metal salt such as calcium chloride. These components react to form a wet solid. Although it has been shown to outperform virtually all other known fire protection insulation compositions in its class, the material can be difficult to handle due to the fact that it comprises a fairly large percentage of non-chemically bound water which can leach from defects in the container walls.
Currently used compositions utilize a roto-molded plastic shell into which the insulation slurry is poured or injected. After curing, water released from the solidified insulation can migrate to and leak from pinhole defects which sometimes occur in the plastic shell. This creates some difficult quality control problems for the roto-molding vendor. One manufacturing method that was developed to mitigate the problem involved the post-cure insertion of various wicking materials such as cellulose sponge into the insulation fill hole to extract some of the free-water. This did not adversely affect the fire protection performance of the insulation. However, the additional manufacturing step adds to production costs and is a very slow process which can require up to several days to complete.
It is, therefore, highly desirable to create an improved insulation formula which is dry (or at least contains a minimal amount of unbound water) on cure and which provides the same fire protection as the parent material. In order to maintain the essential chemical composition and structure of the original insulation, free water reduction has to be based on chemically or physically binding the water in a way that is independent of the basic reactions that form the parent material. The additives used to reduce free water also tend to increase the rate at which the insulation slurry sets up, thus making it more difficult to mix and pour in large quantities. Thus, methods to counteract this undesirable side effect are also desirable.
3. Objects and Advantages
It is a principal object and advantage of the present invention to provide modified formulations of the aforesaid parent material which preserve all of its original fire protection properties and which make the material essentially dry in the cured state.
Another object and advantage of the present invention is to offer manufacturing methods that facilitate an increase in the set-up time of the insulation slurry while maintaining its desirable properties.
An additional object and advantage of the present invention is to provide a fire protection storage container utilizing the improved insulation materials.
Other objects and advantages of the present invention will in part be obvious, and in part appear hereinafter.